1. Technical Field
The present disclosure relates to an identifying circuit.
2. Description of Related Art
Some electronic devices can be charged or recharged through their USB interface(s). The power to charge or recharge the electronic device may be supplied from another device, such as a computer, or directly from a USB mains power adapter. When the USB interface of the electronic device is connected to a computer through the USB cable, the electronic device is considered a USB connected device and can upload or download data from the computer. If the electronic device is not able to exchange data with the connected device such as when connected to a USB mains power adapter, the electronic device may ignore or shut down the connected USB interface. As a result, a controller of the electronic device must identify whether a computer or a power adapter has been connected to the USB interface. At present, a costly special identifying chip is used to identify the type of interface connected to the electronic device.